Wound treatment apparatus

ABSTRACT

A bandage has a first sheet overlying a wound and located adjacent to it and a top sheet overlying the first sheet. The first sheet has a plurality of discrete passageways overlying the wound and adapted to communicate negative pressure established by a negative pressure source to the wound.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 09/743,737, filed Jan. 16, 2001, now U.S. Pat. No. ______,which is a U.S. National Counterpart Application of International PatentApplication, Serial No. PCT/US99/17877, filed Aug. 6, 1999, which claimspriority to U.S. Provisional Patent Application Ser. No. 60/095,625,filed Aug. 7, 1998, and which claims priority to, and is a divisionalapplication of, U.S. patent application Ser. No. 09/369,113, filed Aug.5, 1999, now U.S. Pat. No. 6,458,109. U.S. Provisional PatentApplication No. 60/095,625, International Patent Application No.PCT/US99/17877, and U.S. patent application Ser. No. 09/369,113 arehereby expressly incorporated by reference herein.

TECHNICAL FIELD

The present invention relates to a wound treatment apparatus. Moreparticularly, the present invention relates to a wound treatmentapparatus for treatment of surface wounds.

BACKGROUND ART

Medical professionals such as nurses and doctors routinely treatpatients having surface wounds of varying size, shape, and severity.Variations in wound type and other patient indications dictatevariations in desired medications for treatment, such as antibiotics,growth factors, enzymes, hormones, insulin, anesthetics, and the like.The nature of a wound further prescribes variations in treatmentprotocols, such as delivery rates for medication and temperaturecontrol.

It is known that controlling the topical atmosphere adjacent a surfacewound can enhance the healing process of the wound, for example bymanipulating the oxygen content and/or humidity, or by providinghyperbaric oxygen as part of a treatment protocol, or by introducingmedicinal agents adjacent the wound surface. See, for example, MadaleneC. Y. Heng, Topical Hyperbaric Therapy for Problem Skin Wounds, 19 J.DERMATOL. SURG. ONCOL. 784 (1993); Theodor Kaufman, M.D., et al., TheMicroclimate Chamber. The Effect of Continuous Topical Administration of96% Oxygen and 75% Relative Humidity on the Healing Rate of ExperimentalDeep Burns, 23 J. TRAUMA 807 (1983); and U.S. Pat. No. 4,969,881 toViesturs, entitled “Disposable Hyperbaric Oxygen Dressing.” The medicalindustry would benefit from a practical system for surface woundtreatment that provides medical professionals with a flexible way tocontrol the topical atmosphere adjacent the wound, including applicationof aerosol medications and atmospheric constituents such as oxygen, aswell as providing for collection of drainage from the wound site.

Several publications establish that surgeons were active years ago inapplying a bandage or cover over a wound to provide a vacuum space abovethe wound to enhance healing. Nevertheless, Wake Forest Universityinventors, while not citing the publications, disclosed a vacuum woundtherapy in U.S. Pat. Nos. 5,645,081 and 5,636,643.

Conventional treatment of a surface wound typically involves placementof a packing or dressing material, such as cotton gauze, directly incontact with the patient's wound. Often there is a need to change thedressing material frequently because it becomes saturated with effluentmaterial discharged from the wound. The frequency of the need to changethe dressing can increase when the care giver applies fluids to thedressing such as a saline solution, peroxide, topical antibiotics, orother medicines dictated by various treatment protocols for differenttypes of wounds.

Changing a wound dressing poses several potential problems for the caregiver. Inadvertent contact with sensitive tissue within and adjacent thewound can cause significant discomfort to the patient as well as furthertrauma to the wound. Exposing the wound to the open atmosphere canincrease the chance of infection. Dressings are typically secured inplace with adhesives, and thus changing the dressing requires removingthe adhesive from the patient's skin, posing risks of pain and trauma tothe patient, especially if there is necrotic tissue. Similarly, thedressing material can bind with tissue within the wound, so thatchanging the dressing can cause tissue loss from the wound, resulting inpain to the patient and retarding the healing process. Medical caregivers and patients both would benefit from a bandage system thatprovides sanitary collection and disposal of material discharged from awound in the course of the treatment and healing process while reducingthe need to remove dressing or packing material placed in contact withthe wound.

SUMMARY OF THE INVENTION

According to various features, characteristics, embodiments andalternatives of the present invention which will become apparent as thedescription thereof proceeds below, the present invention provides awound treatment apparatus which includes a bandage configured to cover awound and a seal about the perimeter of the wound. The bandage providesa cavity over the wound with a fluid supply and a fluid drainage incommunication with the cavity. This cavity may be maintained at lessthan atmospheric pressure to enhance healing as known in the prior art.The present invention comprises enhancements to the prior art.

The wound treatment apparatus, for example, includes a first bandageconfigured to cover a wound. The first bandage includes a first surfaceconfigured to face toward the wound, at least one fluid deliverypassageway through the first surface, at least one fluid drainagepassageway through the first surface and fluid delivery conduit incommunication with the fluid delivery passageway. The apparatus alsoincludes a second bandage coupled with the first bandage. The secondbandage includes a second surface configured to face toward the firstbandage and provide a fluid space between the surfaces and has a fluiddrainage conduit in communication with the fluid drainage passageway.

Another embodiment of the wound treatment apparatus includes a bandageincluding a wound facing surface configured to face toward the wound anda fluid drainage passageway having an opening adjacent the wound facingsurface. A fluid drainage tube is coupled to the fluid drainagepassageway. First and second fluid drainage receptacles are coupled tothe drainage tube. First and second valves are coupled between the fluiddrainage tube and the first and second fluid drainage receptacles,respectively.

An additional embodiment of the wound treatment apparatus includes acover bandage configured to cover a wound and provide a seal on healthyskin tissue about the perimeter of the wound. The cover provides arelatively closed space about the wound which may be held at negativepressure. A fluid supply conduit is fitted between the cover bandage andhealthy skin tissue near the wound. A fluid drainage conduit having atleast one fluid drainage opening is fitted between the cover bandage andthe healthy skin tissue and positioned on healthy skin tissue about thewound and the fluid supply.

A further embodiment of the wound treatment apparatus includes a coverbandage providing a closed seal about a wound and a relatively closedcavity over the wound to be held at a negative pressure. The coverbandage includes a first surface configured to face toward the woundhaving least one fluid delivery passageway disposed through the firstsurface, and at least one fluid drainage passageway disposed through thefirst surface. A second surface is configured to face toward the firstsurface and provide a fluid space between the surfaces. The fluid spaceis segregated into a first chamber and a second chamber, wherein thefirst chamber is formed about the fluid delivery passageway and thesecond chamber is formed about the fluid drainage passageway. A fluiddelivery conduit is in fluid communication with the first chamber andthe fluid delivery passageway. A fluid drainage conduit has at least onefluid drainage opening in fluid communication with the second chamberand the fluid drainage passageway.

A still further wound treatment apparatus includes a cover bandageproviding a closed seal about a wound positioned on a joint having acavity over the wound sized to receive the joint and to be held at anegative pressure. The cover bandage includes a first surface configuredto face toward the wound, at least one fluid delivery passageway throughthe first surface, and a second surface configured to face toward thefirst surface providing a fluid space between the surfaces. A fluiddelivery conduit is in fluid communication with the fluid space and thefluid delivery passageway. A fluid drainage conduit having at least onefluid drainage opening is also in fluid communication with the cavity.

Within the present invention, in combination with such a cover bandage,the fluid delivery to the wound may include nebulizers, liquidmedication pumps, recirculating temperature regulated fluid tubes,heaters, temperature and pressure sensors, control valves, oxygensupplies, and controllers as described and claimed hereinafter. All ofthese features, including the vacuum feature, may be programmed to occuron prearranged schedules to deliver care-giver established protocols.

Additional features of the invention will become apparent to thoseskilled in the art upon consideration of the following detaileddescription exemplifying the best mode of carrying out the invention aspresently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to the attacheddrawings which are given as non-limiting examples only, in which:

FIG. 1 is a perspective view of a wound treatment apparatus according tothe present invention;

FIG. 2 is a schematic block diagram of a wound treatment apparatusaccording to the present invention;

FIG. 3 is a schematic block diagram of an alternative embodiment woundtreatment apparatus;

FIG. 4 is an exploded perspective view of a two-piece bandage assemblyaccording to the present invention;

FIG. 5 is a top view of the bottom sheet of the medicinal deliverybandage of FIG. 4;

FIG. 6 is a top view of the top sheet of the medicinal delivery bandageof FIG. 4;

FIG. 7 is a top view of the medicinal fluid supply and temperaturecontrolled, recirculating fluid tubes of FIG. 4;

FIG. 8 is an end view of the medicinal fluid supply and temperaturecontrolled, recirculating fluid tubes of FIG. 7;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 1;

FIG. 10 is a top view of the bandage assembly of FIG. 1 with portionsbroken away;

FIG. 11 is an exploded perspective view of an alternative embodiment ofa bandage assembly;

FIG. 12 is a perspective view of another alternative embodiment of abandage assembly;

FIG. 13 is a perspective view of yet another alternative embodiment of abandage assembly;

FIG. 14 is an exploded perspective view of an alternative embodiment ofa drainage bandage;

FIG. 15 is a diagrammatic perspective view of an alternative embodimentof a wound treatment apparatus;

FIG. 16 is a plan view of a recirculating fluid path assembly from theheating assembly of FIG. 15;

FIG. 17 is a perspective view of the fluid path assembly of FIG. 16;

FIG. 18 is an exploded perspective view of the radiant heating plate ofthe heating assembly of FIG. 15;

FIG. 19 is a system block diagram of an alternative drainage systemembodiment;

FIG. 20 is an exploded view of a wound treatment assembly and amedicinal fluid supply system including an additional embodiment of thepresent invention;

FIG. 21 is a top view of the wound treatment assembly from FIG. 20;

FIG. 22 is a sectional view of the circulating fluid tube from the woundtreatment assembly of FIG. 20, taken along line A-A;

FIG. 23 is a top view of a wound treatment assembly including anotherembodiment of the present invention;

FIG. 24 is a sectional view of the wound treatment assembly from FIG.23, taken along line B-B;

FIG. 25 is a top view of a wound treatment assembly in accordance with astill further embodiment of the present invention;

FIG. 26 is a sectional view of the wound treatment assembly from FIG.25, taken along line C-C;

FIG. 27 is a top view of a wound treatment assembly in accordance withan additional embodiment of the present invention;

FIG. 28 is a sectional view of the wound treatment assembly from FIG.27, taken along line D-D;

FIG. 29 is a sectional view of the wound treatment assembly from FIG.27, taken along line E-E;

FIG. 30 is a top view of a flexible wound treatment assembly inaccordance with the present invention;

FIG. 31 is a sectional view of the flexible wound treatment assemblyfrom FIG. 30, taken along line F-F; and

FIG. 32 is a sectional view of the flexible wound treatment assemblyfrom FIG. 31, applied over a wound on a bendable joint.

FIG. 33 is a perspective view of a wound treatment apparatus including aheating system.

FIG. 34 is a perspective clear view of a portion of the wound treatmentapparatus from FIG. 33.

DETAILED DESCRIPTION OF DRAWINGS

Referring now to the drawings, FIG. 1 illustrates a wound treatmentapparatus 10 that includes a bandage assembly 12 coupled to a patient'sskin 14 adjacent a surface wound 16. Apparatus 10 includes a woundtemperature control system 17, a wound drainage system 19, and amedicinal fluid supply system 15 including a nebulizer 26 shown in FIGS.2 and 3. Wound treatment apparatus 10 provides a system for controllingthe topical atmosphere adjacent wound 16, including delivery ofmedication, control of atmospheric constituents, temperature regulation,and collection of wound drainage.

Including a nebulizer 26 (see FIGS. 2 and 3) in wound treatmentapparatus 10 provides for delivering nebulized fluid containingdissolved wound treatment constituents, such as oxygen or medication, tothe wound. As a wound heals it develops a liquid layer on its externalsurface. This liquid layer forms a barrier that impedes flow ofatmospheric constituents, such as oxygen or medication, to the cells inthe wound, because these constituents must diffuse through the liquidlayer. Application of nebulized fluid improves treatment and healingbecause the nebulized fluid can readily mix with the liquid layer. Thisallows the dissolved constituents in the nebulized fluid to be readilydiffused through the liquid layer and absorbed into the cells below.

Bandage assembly 12 is a two-part assembly that includes a fluidmedication delivery bandage 18 and an adsorbent drainage bandage 20.Drainage bandage 20 is configured to be removably coupled to deliverybandage 18 as shown, for example, in FIGS. 2 and 3. Delivery bandage 18provides for sealing the wound site from the ambient atmosphere so thatsupply system 15, temperature control system 17, and drainage system 19can regulate the wound environment. By providing a two-piece, removablycoupled bandage arrangement, bandage assembly 12 allows for changing thedrainage bandage without the need to remove delivery bandage 18 from thepatient's skin 14.

Delivery bandage 18 includes a medicinal fluid supply tube 22 and iscoupled to the patient's skin 14 over wound 16. Delivery bandage 18 canremain in place while drainage bandage 20 can be changed as neededduring wound treatment. Drainage bandage 20 includes a wound drainagetube 24 that is coupled to wound 16 through delivery bandage 18 to allowfluid from wound 16 to exit from bandage assembly 12, the fluidincluding both fluids secreted by wound 16 as well as fluids enteringbandage 18 through medicinal fluid supply tube 22. Bandage assembly 12thus allows control of the topical atmosphere adjacent wound 16 whilelimiting the exposure to atmospheric contaminants, allowing for use oftreatment protocols to enhance healing while reducing opportunities forpotential infection and trauma.

Medicinal fluid supply system 15 of wound treatment apparatus 10illustratively includes nebulizer 26 and an optional liquid medicationpump 39 as shown in FIGS. 2 and 3. Temperature control system 17includes a heater 40 and pump 42. Drainage system 19 includes a drainagebag 92 as shown in FIG. 2 or alternatively a vacuum pump 98 and liquidtrap bottle 96 as shown by 19′ in FIG. 3.

Nebulizer 26 includes an input port 28 for accepting a nebulizer gasinput, such as standard air or pure oxygen, a nebulized fluid outputport 30, and a liquid reservoir 32 coupled between input and outputports 28, 30. Liquid reservoir 32 illustratively contains medication asneeded to implement a treatment protocol for wound 16, such asantibiotics, growth factors, enzymes, hormones, insulin, anesthetics,and the like. It is understood that reservoir 32 can contain any fluid,such as pure water or a saline solution. Nebulizer 26 is illustrativelya Mini Heart model manufactured by Vortran, which can atomizeapproximately 4 milliliters per hour of liquid medication at an inputgas flow rate of approximately 1.5 liters per minute. It is understood,however, that any suitable nebulizing device can be used.

Nebulizer output port 30 is coupled to medicinal fluid supply tube 22 ofdelivery bandage 18 of bandage assembly 12. Optionally, a liquidmedication pump 39 such as an IV pump can also be coupled to medicinalfluid supply tube 22. Wound treatment apparatus 10 thus provides fordelivery of either aerosol or liquid medication or both to wound 16through delivery bandage 18.

As discussed in more detail below, delivery bandage 18 further includesa recirculating fluid tube 34 having an input port 36 and an output port38. Wound treatment apparatus 10 includes a heater 40 and a peristalticpump 42 coupled between the input and output ports 36, 38 ofrecirculating fluid tube 34. Temperature control system 17 thus allowstemperature controlled liquid to flow through bandage assembly 12 toregulate the temperature at the site of wound 16.

Peristaltic pump 42 is illustratively a Model 313 manufactured by WatsonMarlow, using a nominal flow rate of between 200 to 250 milliliters perminute. Although a peristaltic pump driven by an AC synchronous motor at72 RPM is used because its disposable tubing elements eliminate the needto clean the pump between patient uses, it is understood that other pumpdesigns such as centrifugal, gear-driven, or diaphragm type pumps can beused.

Heater 40 illustratively is a specially designed tubular unit thatincludes a tubular housing 37, a 100 watt heater element 35 positionedwithin housing 37, and a thermocouple 33 for monitoring the temperatureof heater element 35. A fluid reservoir 41 is configured to fit withinhousing 37 so that heater element 35 can heat the recirculating fluid.As discussed below, other suitable heating systems can be used.

Fluid reservoir 41 illustratively is formed from a rubber silicone tubeconfigured to fit snugly within housing 37. Reservoir 41 advantageouslyis provided as a prepackaged unit with bandage assembly 12 along withassociated tubes to prevent spillage that can accidentally occur if anopen container is used for the recirculating fluid. It is understood,however, that other suitable devices for controlling the temperature ofthe recirculating fluid can be used, such as an immersion heaterconfigured to be placed within an open fluid reservoir (not shown), oralternative embodiment heating assembly 200 as shown in FIGS. 14-18 anddiscussed in detail below.

Wound treatment apparatus 10 further includes a computer-basedelectronic control system 44 that is coupled electronically to theelectronic and electromechanical components such as nebulizer 26,peristaltic pump 42, heater 40 and thermocouple 33. Control system 44provides for automated control of wound treatment apparatus 10 forvarious treatment protocols, for example to regulate temperature at thewound site by using heater 40 and pump 42 to regulate recirculatingfluid temperature to 37° Celsius.

Control system 44 illustratively is directly coupled to the controlledcomponents using analog, discrete, and serial I/O signals as required bythe various component interfaces. It is understood that thecommunication mechanism can include any type of electronic network, suchas any serial bus or parallel bus architecture. The communicationsprotocol similarly can vary. For example, master-slave, token ring, orpeer-to-peer communication protocols, such as Ethernet or EchelonLONworks™, can be used. By providing software control of wound treatmentapparatus 10 components such as nebulizer 26, heater 40, and pump 42,control system 44 can automatically control the delivery of aerosolmedication, temperature, and oxygen concentration levels at the site ofwound 16 to implement a desired treatment protocol and to provide anoptimal wound healing environment.

Nebulizer input port 28 is coupled to a nebulizer gas input assembly 46that includes air and oxygen input ports 48, 50, an air compressor 52,air and oxygen pressure regulators 54, 56, a selector valve 58, and anebulizer gas input filter 60. Filter 60 is illustratively a single usedisposable bacteria filter.

Oxygen input port 50 can illustratively be coupled to a standardhospital oxygen blender 62 through a standard hospital air filter andwater trap 64. An internal compressed oxygen supply (not shown) canreplace oxygen blender 62. Oxygen filter and water trap 64 contains a 5micron filter element and catch basin to trap particulate matter andcondensed water output from oxygen blender 62. Blender 62 furtherillustratively includes an oxygen flowmeter 66 such as a standardhospital pediatric flowmeter that allows a flow set range of, forexample, between zero and three liters per minute.

Air compressor 52 is coupled to nebulizer air input port 48 through anexternal air filter and water trap 68. Similar to supply of oxygen, anexternal compressed air supply (not shown) can also be used. Aircompressor 52 is illustratively a diaphragm type pump driven by abrushless DC motor that can deliver a minimum of 1.3 liters per minuteat 15 psi. Compressor 52 includes an input filter (not shown) having a25 micron filter/silencer. Similar to oxygen filter and water trap 64,air filter and water trap 68 contains a 5 micron filter element andcatch basin for trapping particulate matter and water droplets from thecompressed air output from compressor 52.

Air and oxygen input ports 48, 50 are coupled to selector valve 58through air and oxygen pressure regulators 54, 56, respectively.Regulators 54, 56 maintain air and oxygen pressure between about 15 andabout 17 psi. Air pressure regulator 54 vents excess air outside ofwound treatment apparatus 10 through an air vent 70 and oxygen pressureregulator vents through oxygen vent 72.

Selector valve 58 is coupled electronically to control system 44 toallow for software control of the mixing of air and oxygen so that thegas input to nebulizer 26 can range from pure air to pure oxygen.Selector valve 58 can eliminate the need for external oxygen blender 62.Selector valve 58 illustratively switches between air and oxygen at apredetermined rate, although other valve arrangements can be used to mixair and gas, such as a dual input mixing valve, a pair of butterflyvalves or other valve configurations for mixing two fluid input streams.Control system 44 can be used to supply an air/oxygen treatment protocolto the wound site automatically. For instance, control system 44 canimplement a programmed protocol to deliver 3 hours of air followed by 3hours of oxygen, and so on, to the wound site. Valve 58 automaticallyswitches to implement the programmed protocol.

Nebulizer gas input assembly 46 further includes an air pressure sensor74 coupled between selector valve 58 and air pressure regulator 54, anoxygen pressure sensor 76 coupled between selector valve 58 and oxygenpressure regulator 56, and a nebulizer gas input pressure sensor 80coupled between selector valve 58 and nebulizer input port 28. Sensors74, 76, 80 are coupled to control system 44 to provide feedback formonitoring of proper system operation and so that an alarm can beindicated and wound treatment apparatus 10 shut down automatically if apressure signal exceeds a predetermined threshold.

Wound treatment apparatus 10 also includes a nebulizer empty sensor 78to indicate if nebulizer 26 is empty. Nebulizer empty sensor 78 providesa feedback signal to electronic control system 44 and illustratively isan acoustical sensor. Control system 44 continuously monitors the outputsignal from sensor 78, which changes distinctively when reservoir 32becomes empty, at which point an alarm can be signaled and woundtreatment apparatus 10 shut down. It is understood that other types ofsensors can be used to determine if nebulizer 26 is empty, such as, forexample, capacitive sensors, float switches, or optical, infrared, orultrasonic sensors.

Wound treatment apparatus 10 further includes a nebulizer pressuresensor 80 coupled between selector valve 58 and nebulizer input port 28.Pressure sensor 80 provides a feedback signal to control system 44indicative of pressure within nebulizer 26 and is also used to verifythe proper operation of selector valve 58. Wound treatment apparatus 10furthermore includes a tilt sensor 82 and a bandage interface pressuresensor 84, both coupled to control system 44. Tilt sensor 82 signals analarm and shuts down apparatus 10 if apparatus 10 is tilted beyond apredetermined threshold, illustratively 30°.

Bandage interface pressure sensor 84 is coupled between nebulizer outputport 30 and medicinal fluid supply tube 22 of bandage assembly 12. Bymonitoring back pressure from the bandage, pressure sensor 84 allowscontrol system 44 to provide a display indicative of pressure at theinterface between delivery bandage 18 or between the patient and a bedwhen the patient is lying directly on bandage assembly 12. Controlsystem 44 can also signal an alarm and shut down apparatus 10 ifinterface pressure exceeds a predetermined threshold.

Pressure on a wound can cause further skin breakdown, especially if thewound is a decubitus ulcer or bed sore. The wound interface pressurefrom sensor 84 can be used as a feedback signal to a bed control or asupport surface control to adjust a therapy surface. Sensor output 84can also signal the care giver through the control system and a nursecall system so that the care-giver can move the patient, either on theexisting mattress or to a reduced pressure support surface, for treatingthe wound.

Temperature control system 17 includes heater 40, reservoir 41, and pump42. Fluid reservoir 41 includes an input port 43 coupled to output port38 of recirculating fluid tube 34 and an output port 45 coupled to atube feeding peristaltic pump 42.

Peristaltic pump 42 includes a pump input port 47 coupled to reservoiroutput port 45 and a pump output port 49 coupled to input port 36 ofrecirculating fluid tube 34. A pump output temperature sensor 86 and apump safety shutoff temperature sensor 88 both are coupled between pumpport 49 and recirculating fluid input port 36 of bandage assembly 12.

Pump output temperature sensor 86 provides a feedback to control system44 for closed loop control of heater 40 to control fluid inputtemperature to tube 34 in bandage assembly 12 to a desired temperature,illustratively 37° Celsius. Safety shutoff temperature sensor 88 issimilarly provided as a feedback to control system 44 and is used todisable and alarm apparatus 10 if recirculating fluid temperatureexceeds a safe limit, such as 41° Celsius. Sensors 86, 88 illustrativelyare non-contact, infrared sensors such as an IRt/c.01HB-J-37C sensorfrom Exergen Corp., although it is understood that other suitablesensors can be used.

Optionally, proximity sensors (not shown) can be used to ensure thattemperature sensors 86, 88 are properly coupled. For example,temperature sensors 86, 88 and respective proximity sensors can becoupled to a housing or channel into which a tube from recirculatingfluid supply input port 36 is installed. If the proximity sensors do notdetect the tube's presence within the channel, control system 44 canreact accordingly, such as by providing a suitable display and/or alarmand/or by shutting down the system.

Temperature control system 17 further includes a liquid leak sensor 90coupled adjacent pump 42 to monitor leaks from pump 42 or adjacenttubing. Sensor 90 is illustratively a capacitive sensor pad locatedunder peristaltic pump 42. Sensor 90 provides a signal to electroniccontrol system 44, which can alarm and disable wound treatment apparatus10 if a leak is detected.

Wound treatment apparatus 10 further includes a wound effluent drainagereceptacle or bag 92 that collects fluid flowing from bandage assembly12 out of drainage tube 24, including both fluid supplied into bandageassembly 12 from supply tube 22 and discharge from wound 16. Drainagebag 92 includes a vapor filter 94 to filter gaseous components of fluidexiting bandage assembly 12. Vapor filter 94 is illustratively astandard hospital ventilator exhaust filter configured to plug directlyinto the side of drainage bag 92.

An alternative embodiment wound treatment apparatus 10′ is shown in FIG.3. Apparatus 10′ replaces wound effluent drainage bag 92 and vaporfilter 94 of apparatus 10 with a liquid trap bottle 96, a vacuum pump98, and a vacuum filter 100 coupled between trap bottle 96 and pump 98.Liquid trap bottle 96 is coupled to drainage tube 24 to collect liquidsin the fluid flow from bandage assembly 12. Vacuum pump 98 is used toapply a negative pressure to facilitate drainage. If desired, sufficientnegative pressure can be applied so that negative pressure on the woundfacilitates its closure. Filter 100 illustratively is a hydrophobicbacteria filter coupled between trap bottle 96 and vacuum pump 98.

Referring now to FIGS. 4-10, bandage assembly 12 includes deliverybandage 18 and drainage bandage 20. Delivery bandage 18 includes bottomand top sheets 102, 104 that sandwich both medicinal fluid supply tube22 and recirculating fluid tube 34. Drainage bandage 20 includes bottomand top sheets 106, 108 that sandwich an adsorbent pad 110 and drainagetube 24. Adsorbent pad 110 is illustratively formed from medical gradehydrophilic foam, although any suitable material such as an absorbentsubstance can be used. Bandage sheets 102, 104, 106, 108 areillustratively formed from clear, flexible polyurethane or vinyl thatmeets USP Class VI requirements for medical applications.

Delivery bandage bottom sheet 102 is formed with a generally squareperimeter 112 having rounded corners 114 and a tab 116 along a side ofperimeter 112 as best shown in FIG. 5. Bottom sheet 102 further includesa central wound drainage passageway 118, a plurality of medicinal fluidsupply passageways 120 arranged in a circular pattern concentric withpassageway 118, and a plurality of outer wound drainage passageways 122arranged in another concentric circular pattern radially outward ofdelivery passageways 120. Delivery passageways 120 provide for deliveryof fluid medications from medicinal fluid supply tube 22 to wound 16 andillustratively are relatively smaller than drainage passageways 118, 122that provide for passage of wound drainage through delivery bandage 18.

Delivery bandage top sheet 104 is formed to include a perimeter 124, tab126, central passageway 128, and outer passageways 130 that areconfigured to align with perimeter 112, tab 116, central passageway 118,and outer passageways 122 of bottom sheet 102 as best shown in FIG. 6.When top and bottom sheets 102, 104 are aligned, central passageways118, 128 and outer passageways 122, 130 are in fluid communication andallow wound effluent to pass through bandage 18.

Medicinal fluid supply tube 22 and recirculating fluid tube 34illustratively are contained within a multi-lumen tube 132 as best shownin FIGS. 7 and 8. It is understood that separate tubes can be used.Multi-lumen tube 132 is a 65 durometer USP Class VI polyvinyl chloridetriple lumen tube and has three channels, one of which defines supplytube 22 and the other two define portions of recirculating fluid tube34. Tube 132 includes a terminal end 134 that defines an end ofmedicinal fluid supply tube 22.

Recirculating fluid tube 34 further includes a straight segment 136 thatextends axially outward from end 134 and a generally circular segment138 coupled to straight segment 136 as best shown in FIG. 7. Thegeometry of recirculating fluid tube 34 can vary as needed to distributetemperature controlled fluid throughout delivery bandage 18. Temperatureregulated fluid, illustratively water, is circulated through deliverybandage 18 in segments 136, 138 from temperature control system 17 tomaintain bandage 18 at an optimal temperature for wound treatment. It isunderstood that the temperature of bandage 18 can be regulated bycontrol system 44 according to a desired treatment protocol, for exampleby maintaining a temperature to maximize treatment effectiveness of anenzyme or other medicinal fluid supplied through medicinal fluid supplytube 22.

Delivery bandage 18 is formed by sandwiching multi-lumen tube 132between top and bottom sheets 102, 104 so that tube 132 extends overtabs 116, 126 and circular segment 138 is concentric with centralpassageways 118, 128 as best shown in FIG. 10. Top and bottom sheets102, 104 are bonded together by radio frequency (RF) welding. CircularRF welds 140, 142 seal the perimeter around each pair of aligned wounddrainage passageways 118, 128, and 122, 130. A perimeter RF weld 144seals the aligned perimeters 112, 124.

A fluid delivery chamber weld 146 extends from perimeter weld 144 andencompasses inner wound drainage passageway weld 140 to define a fluiddelivery chamber 148 that is in fluid communication with deliverypassageways 120 in bottom sheet 102 and terminal end 134 of medicinalfluid supply tube 22. Thus, aerosol or liquid medications suppliedthrough medicinal fluid supply tube 22 from nebulizer 26 or medicinalpump 39 can be delivered through delivery bandage 18 to wound 16 throughchamber 148 that is isolated from wound drainage passageways 118, 122,128, 130. Recirculating fluid tube 34 illustratively is contained withindelivery chamber 148, although it is understood that tube 34 could beisolated from chamber 148.

Delivery bandage 18 further includes a sealing gasket 150 coupled tobottom sheet 102 adjacent its perimeter 112 as shown in FIGS. 4 and 9.Gasket 150 is illustratively a thin foam frame that includes an adhesivecoating for coupling gasket 150 both to bottom sheet 102 and forremovably coupling gasket 150 to a patient's skin 14. Gasket 150provides an improved seal between bottom sheet 102 of delivery bandage18 and skin 14 to allow wound treatment apparatus 10 to control thetopical atmosphere adjacent wound 16. It is understood that othersuitable materials can be used to provide a gasket, such as anappropriate layer of adhesive material.

Bottom sheet 106 of drainage bandage 20 includes a perimeter 152,central drainage passageway 154, and outer drainage passageways 156 thatare configured to align with the corresponding perimeter 124 andpassageways 128, 130 of top sheet 104 of delivery bandage 18. Bottomsheet 106 includes a thin layer of adhesive 158 formed as an open frameadjacent perimeter 152 to provide for removably coupling to deliverybandage top sheet 104. Adhesive 158 is configured to remain on bottomsheet 106 of drainage bandage 20 after uncoupling to allow for easyreplacement of drainage bandage 20 without the need to remove deliverybandage 18.

Top sheet 108 of drainage bandage 20 has no passageways and isconfigured to align with bottom sheet 106 to provide a cavity 160 thatreceives adsorbent pad 110. Drainage bandage 20 is formed by sandwichingdrainage tube 24 between top and bottom sheets 106, 108, which are thensealed together by RF welding adjacent their perimeters. Drainagebandage 20 thus channels wound effluent from delivery bandage 18,through pad 110, and out drainage tube 24 in an assembly that is easilyreplaceable, for example when adsorbent pad 110 becomes saturated orotherwise contaminated.

Bandage assembly 12 thus provides a two-piece bandage in which drainagebandage 20 can be removed and replaced while leaving delivery bandage 18in situ. Drainage passageways 118, 122, 128, 130 thus allow for accessto wound 16 through delivery bandage 18 when drainage bandage 20 isremoved. Thus, a medical care giver can take a culture or sample fromwound 16 without the need to remove delivery bandage 18.

An alternative embodiment bandage assembly 12′ includes a one-piececombination delivery and drainage bandage comprising a delivery bandageportion 18′ and drainage bandage portion 20′ as shown in FIG. 11.Delivery bandage portion 18′ includes a bottom sheet 102′ that has asingle drainage passageway 118′ and a plurality of medicinal fluiddelivery passageways 120′. Top sheet 104′ includes a single drainagepassageway 128′. Delivery bandage portion 18′ includes a medicinal fluidsupply tube 22′ for use as discussed above in providing nebulized orliquid medication, etc. Drainage bandage portion 20′ includes a pad110′, a top sheet 108′, and a drainage tube 24′. Drainage tube 24′ iscoupled to bandage assembly 12′ between sheets 104′ and 108′.

Another alternative bandage assembly 12″ is formed with only top andbottom sheets 102″, 104″ as shown in FIG. 12. Bottom sheet 102″ includesa central drainage passageway 118″ and a plurality of deliverypassageways 120″ arranged in a circular pattern radially outward ofdrainage passageway 118″. A medicinal fluid supply tube 22″ and adrainage tube 24″ are coupled between top and bottom sheets 102″, 104″,with radio frequency welds (not shown) isolating the delivery tube andpassageways 22″, 120″ from drainage tube 22″ and passageway 118″.

Yet another alternative bandage assembly 12′″ is formed with elongatedtop and bottom sheets 102′″, 104′″ as shown in FIG. 13. Deliverypassageways 118′″ are arranged in a rectangular pattern to provide fordelivery of fluid medication and control of the topical atmosphereadjacent a surface wound 16 having an elongated shape. Drainagepassageway 120′″ is illustratively circular, although drainagepassageway 120′″ can be formed in any suitable shape, such as anelongated rectangular or elliptical opening. Embodiment 12′″ illustrateshow bandages according to the present invention can readily be adaptedfor treatment of any wound shape by suitable geometric adaptations ofthe bandage assembly.

Another alternative drainage bandage 20″ includes a bottom sheet 106″, atop sheet 108″, and a pad 110″ as shown in FIG. 14. Bottom and topsheets 106″, 108″ are formed with respective passageway portions 107″,109″. Bandage 20″ is formed by welding sheets 106″, 108″ together attheir perimeters so that passageway portions 107″, 109″ form apassageway suitable for coupling to a drainage tube 24. Bandage 20″ canbe used as discussed above for bandage 20 so that wound effluent from adelivery bandage travels through drainage bandage 20″ as shown by arrows99″, 101″.

As mentioned above, heater 40 can be replaced by other heating systems,such as recirculating fluid heating assembly 200 as shown in FIGS.15-18. FIG. 15 also shows yet still another alternative embodimentbandage assembly 12″″. Bandage assembly 12″″ includes a delivery bandageportion 18″″ that differs from delivery bandage 18 as shown in FIGS. 4-6essentially in its outer wound drainage passageways 122″″, which areformed as truncated arc segments. Bandage assembly 12″″ includes adrainage bandage portion 20″″ essentially the same as drainage bandage20″ discussed just above. Bandage assembly 12″″ further includes adrainage tube 24 coupled to a wound drainage vapor filter 94.

Heating assembly 200 includes a radiant heating plate 202 configured tobe coupled with a recirculating fluid path assembly 204 that transportsrecirculating fluid in a circuitous path past plate 202. As shown inFIG. 15, fluid path assembly 204 includes a tube section 206 configuredto be laced into a channel 208 in a peristaltic pump 42 that pumps therecirculating fluid through assembly 200. Fluid path assembly 204further includes input and output ports 210, 212 that are coupled to anebulizer cap 214, which in turn is coupled both to a nebulizer 26 andto a multi-lumen tube 132 leading to bandage assembly 12″″. Tube 132 iscoupled to bandage assembly 12″″ by a connector 216.

Fluid path assembly 204 is illustratively formed by welding two flexibleplastic sheets together to form a circuitous fluid input pathway 218 anda circuitous fluid output pathway 220 as shown in FIG. 16. Input pathway218 is coupled to input port 210 and tube section 206; output pathway220 is coupled to tube section 206 and output port 212. Fluid pathassembly 204 is folded along its centerline 222 as shown in FIG. 17 sothat input pathway 218 is opposite output pathway 220. Side edges 224,226 that extend from centerline 222 are then welded together as shown byarrows 230 to create a pocket 228 configured to receive heating plate202 so that recirculating fluid travels circuitously through fluid pathassembly 204 past heating plate 202.

As fluid flows through fluid path assembly 204 past heating plate 202,fluid temperature is measured, for example, by infrared heat sensors238. Recirculating fluid temperature is then regulated to a desiredvalue by controlling the heat output of plate 202 selectively based onmeasured fluid temperature. It is understood that fluid path assembly204 can be replaced by any suitable mechanism, such as a tube coupled toflexible sheets, or by forming narrow pathways or parallel pathwayswithin flexible sheets, etc. Essentially, the requirement is to providerecirculating fluid pathways capable of receiving heat from plate 202 inorder to regulate the temperature of fluid flowing through the pathways.

Heating plate 202 is illustratively formed from two plate sections 228,230 that are coupled to a base 232 as shown in FIG. 18. Plate sections228, 230 include resistive heating elements 234 that are selectivelycontrollable to heat recirculating fluid as it flows in fluid pathassembly 204 past plate 202. Plate sections 228, 230 further includeholes 236 to facilitate use of infrared temperature sensors formeasuring recirculating fluid temperature. Plate 202 and sensors 238 arecoupled to control system 44 to provide for automated temperaturecontrol of recirculating fluid.

An alternative drainage system 162 as shown in FIG. 19 can be used inthe wound treatment apparatus 10, 10′ of FIGS. 2 and 3 to provide forautomated monitoring and switching of drainage bags by control system44. Drainage system 162 includes first and second drainage bags 164,166, and valves 168, 170 that are coupled between drainage bags 164, 166and wound drainage tube 24. Drainage bags 164, 166 include pressuresensors 172, 174 that provide signals to control system 44 indicative ofbag pressure, which correlates to whether the bag is full and needs tobe changed. Bags 164, 166 further include bacteria filters 190, 192 andexhaust valves 186, 188 that control system 44 can use to vent excesspressure from within bags 164, 166.

Drainage bags 164, 166 are coupled to a pump 176 through valves 178,180, pressure regulator 182, and filter 184. Valves 168, 170 are coupledto control system 44 to allow for automated selection of which drainagebag will receive effluent from bandage assembly 12, 12′. Drainage system162 thus allows for automated and continuous operation of woundapparatus 10, 10′. In operation, valve 170 is closed and valve 168 isopened to permit filling of bag 164. When sensor 172 indicates tocontrol system 44 that bag 164 is full, valve 168 is closed and valve170 is opened to permit filling of bag 166. With valve 168 closed, valve178 opens to supply pressure to bag 164 to force the contents of bag 164out through bacteria filter 190. When sensor 174 detects that bag 166 isfull, valve 170 is closed and valve 168 is opened to permit filling ofbag 164 again. With valve 170 closed, valve 180 opens to supply pressureto bag 166 to force the contents of bag 166 out through bacteria filter192. This cycle repeats itself so that tube 24 is not exposed to backpressure.

Referring now to FIGS. 20 and 21, an additional embodiment of woundtreatment apparatus 320 comprises a medicinal fluid supply 322 todeliver fluid to wound 16, and a vacuum 326 and waste receptacle 324 todraw and store the fluid from wound 16. A supply tube 328 is connectedto fluid supply 322 and to a fluid junction array 330. Fluid junctionarray 330 includes a fluid delivery conduit or deposit membrane 332having an opening 333, and a circulating tube coupler 334. Opening 333is positioned near wound 16. Illustratively, deposit membrane 332 can bemade from two sheets laterally sealed on each side or it can be madefrom a simple tube. The material used to make membrane 332 can berubber, plastic or any other suitable material. In addition, in oneillustrative embodiment, membrane 332 has a flare 338 leading to opening333, as best shown in FIG. 21. Flare 338 allows selective control overthe flow rate of the medicinal fluid. The operator may cut membrane 332thereby reducing its length, and increasing the flow of the medicine.The more flare 338 that is cut off, the faster the flow rate.

Circulating tube coupler 334 illustratively comprises dual ends 340 and342, respectively. Each end illustratively 340 and 342 extend fromopposite sides of membrane 332. (See FIG. 21.) Circulating tube 344 isconnected to each end 340 and 342 encircling the periphery of wound 16on healthy tissue. Fluid collection openings or notches 346 are formedintermittently along the length of tube 344. Illustratively, end 342 isconnected to outlet tube 348 whereas end 340 is a terminated end. Thisforces all of the fluid in tube 344 to travel in one direction towardoutlet tube 348. As a result, fluid flows out from membrane 332 passingover wound 16, drawing through notches 346 into tube 344, and exitingthrough outlet tube 348. Vacuum 326 communicates with outlet tube 348via vacuum tube 350 and waste receptacle 324 to assist in drawing fluidfrom wound 16 into waste receptacle 324.

Circulating tube 344 may include a bendable wire 352 extendingtherethrough. Bendable wire 352 provides a semi-ridged form for tube 344so that it may be selectively positioned about the periphery of wound 16and hold its shape. As shown in FIG. 22, diameter 358 of bendable wire352 is less than inner diameter 354 of circulating tube 344, thereby notinhibiting the flow of fluid.

Fluid junction array 330 attaches to adhesive 361 which adheres to aportion of healthy tissue surrounding wound 16. It is appreciated,however, that array 330 may be attached to the skin by any variety ofsuitable means. Top sheet 362 is sized to cover apparatus 320 and may beremovably attached directly to healthy skin (not shown). Top sheet 362is illustratively formed from a clear, flexible polyurethane or vinylthat meets USP Class VI requirements for medical applications. Gasket orborder 360 is illustratively formed with a generally square perimeterhaving rounded corners attaching to the skin about the periphery of tube344 and serves as a seal. In one embodiment, border 360 is positionedunderneath top sheet 362, as shown in FIG. 21. In addition, border 360attaches to array 330 by a pair of fasteners 364 that extend throughapertures 366.

Another embodiment of the wound treatment apparatus is indicated byreference number 368 and is shown in FIGS. 23 and 24. A fluid supplytube 382 leads illustratively into outer chamber 378. Outer chamber 378is formed about the periphery of inner chamber 374. Chambers 374 and 378are formed by a top sheet and a bottom sheet 372 and 373, respectively.(See FIG. 24.) Illustratively, RF welds about the periphery of innerchamber 374 and about the periphery of outer chamber 378 further definesthe chambers within sheets 372 and 373. The welds form an inner borderand an outer border 375 and 380, respectively. It is understood that anysuitable means can be used to form borders 375 and 380, in place ofultra-sonic welds. For example, borders 375 and 380 can be made fromadhesive or from heat selectively applied to sheets 372 and 373.

A gasket 383 is attached about outer border 380 of the bandage. Gasket383 suspends sheets 372 and 373 forming a wound cavity 379 as shown inFIG. 24. An adhesive 384 is attached to the underside of gasket 383 toadhere to healthy skin tissue surrounding the wound (not shown) therebyholding apparatus 368 in place and containing the medicinal fluid inwound cavity 379.

Illustratively, medicinal fluid is deposited through tube 382 into outerchamber 378. Several passageways 377 are disposed, in spaced relation toeach other, through lower sheet 373 into wound cavity 379. Medicinalfluid can then flow through passageways 377 into wound cavity 379 andonto the wound. The fluid is then drawn from the surface of the wound upthrough outlet aperture 376. Outlet aperture 376 is disposed throughlower sheet 373 into inner chamber 374. With the assistance of a vacuumconnected to outlet tube 370, the medicinal fluid is drawn from innerchamber 374 into tube 370 and ultimately into a waste receptacle. Fluidcollection openings or notches 346 are formed intermittently along thelength of tube 370 within inner chamber 374 to further assist incollecting fluid.

It is appreciated that the flow direction of the medicinal fluid may bereversed from that previously described. Illustratively, medicinal fluidcan enter apparatus 368 through outlet tube 370, and dispense throughaperture 376 into wound cavity 379. Fluid can then be drawn throughapertures 377 into outer chamber 378 and out through tube 382. Apertures377 may be of any size suitable to draw the fluid from wound cavity 379into chamber 378.

A still further embodiment of the wound treatment apparatus is indicatedby reference number 386 and is shown in FIGS. 25 and 26. In contrast tothe previous embodiment, fluid supply tube 382 leads illustratively intoinner chamber 374. Like the previous embodiment, outer chamber 378 isformed about the periphery of inner chamber 374. In addition, chambers374 and 378 are formed by a top sheet and a bottom sheet 372 and 373,respectively. (See FIG. 26.) Again, illustratively, an RF weld about theperiphery of inner chamber 374 and at the periphery outer chamber 378further defines the chambers within sheets 372 and 373. The welds forman inner border and an outer border 375 and 380, respectively. It isunderstood that any suitable means can be used to form borders 375 and380, in place of RF welds.

Illustratively, medicinal fluid is deposited through tube 382 into innerchamber 374. This is in contrast to the previous embodiment where tube382 deposited fluid into outer chamber 378. Medicinal fluid can thenflow through inlet aperture 385 that is disposed through bottom sheet373 into wound cavity 379 and onto the wound. Several passageways 381are disposed, in spaced relation to each other, through lower sheet 373into wound cavity 379. In one illustrative embodiment, passageways 381are larger in size than passageways 377 in the previous embodiment. Thefluid is drawn from the surface of the wound up through passageways 381.In one embodiment, openings or notches 346 are formed intermittentlyalong the portion of tube 391 extended within outer chamber 378. Tube391 illustratively extends through outer chamber 380. With theassistance of a vacuum connected to outlet tube 391, the medicinal fluidis drawn up from outer chamber 378 into tube 391 and ultimately into awaste receptacle. Other features like gasket 383 and adhesive 384 areconfigured similar to that of the previous embodiment.

It is appreciated that the flow direction of the medicinal fluid may bereversed from that previously described. Illustratively, medicinal fluidcan enter apparatus 386 through tube 391, flow out notches 388 anddispense through apertures 381 into wound cavity 379. Fluid can then bedrawn through aperture 385 into inner chamber 374 and out through tube382. Apertures 381 may be of any size suitable to dispense the fluidfrom outer chamber 378 into wound cavity 379.

An additional embodiment of a wound treatment apparatus is indicated byreference number 392 and is shown in FIGS. 27-29. Wound apparatus 392comprises a fluid supply tube 396 extending illustratively near thecenter of apparatus 392 into a dispensing aperture 398. Aperture 398opens to a wound cavity 400 formed on the underside of apparatus 392.(See FIGS. 28 and 29.) Above wound cavity 400 and formed aboutdispensing aperture 398 is basin 402. Basin 402 is defined by inner andouter walls 410 and 412, respectively. Inner wall 410 separates thebasin 402 from dispensing aperture 398. Outer wall 412 illustrativelydefines the periphery of basin 402. Columns 404 extend from basin 402,illustratively in a circular formation about inner wall 410, as shown inFIG. 27. A top sheet 405 is formed over basin 402, attachingillustratively to the top of outer wall 412. Columns 404 support topsheet 405 over basin 402. Top sheet 405 is thereby prevented fromcollapsing in on basin 402 and covering passageways 406 as a negativepressure is applied to bandage 392.

An adhesive 394 is attached to apparatus 392 illustratively about theperiphery of cavity 400. As with previous embodiments, adhesive 394adheres to healthy skin tissue surrounding the wound. It is appreciatedthat adhesive 394 may be replaced with any variety of means to securewound apparatus 392 over the wound.

Illustratively, medicinal fluid flows from tube 396 through aperture 398into wound cavity 400 and onto the wound. The fluid then draws upthrough passageways 406 collecting in basin 402. The collected fluid isthen drawn from basin 402 into outlet tube 414 and ultimately into awaste receptacle (not shown). As with other embodiments previouslydiscussed, a vacuum may illustratively be attached to outlet tube 414 inthe manner previously described.

It is appreciated, however, that the flow direction of the medicinalfluid in apparatus 392 may be reversed from that previously described.Illustratively, medicinal fluid can enter through tube 414, flow intowound cavity 400 through passageways 406. The fluid can then be drawnthrough aperture 398 into tube 396. Apertures 406 may be of any sizesuitable to dispense or draw the fluid to or from wound cavity 400.

Another embodiment of the present invention includes a flexible woundtreatment apparatus 420 shown in FIGS. 30-32. An inlet tube 382 isextended through top panel 422 into chamber 424. Chamber 424 is formedbetween top panel 422, mid-panel 426, and is defined by inner and outerborders 375 and 380, respectively. (See FIGS. 30 and 31.)Illustratively, an RF weld about the peripheries of chamber 424 formsborders 375 and 380 as previously discussed. Several apertures 377 aredisposed through mid-panel 426 into an expanded wound cavity 428. Woundcavity 428 is defined by two laterally spaced side walls 430 and 432 andtwo end walls 434 and 436 extending between said side walls 430 and 432.Mid-panel 426 interconnects to the coplanar edges of walls 430, 432,434, and 436. The resultant form is a flexible bellow or flexible body.A spacer 442 is fitted within the periphery of wound cavity 440. Spacer442 is illustratively made from a foam material but it is understoodthat it can be made from any suitable material that will assist inmaintaining the form of the expanded wound cavity 428 as shown in FIGS.31 and 32.

Formed about the periphery of wound cavity 428 and attached to coplanaredges of said walls 430, 432, 434, and 436 opposite mid panel 426, is apad 438. Pad 438 is illustratively made from a thin flexible foammaterial and often with a plastic-like top coating. Pad 438 provides acushioning intermediary between the walls 430, 432, 434, and 436, and anadhesive 440. Adhesive 440, is a similar panel to those adhesivesdescribed in the previous embodiments.

Flexible wound treatment apparatus 420 is optimum for use on flexiblejoints like knees and elbows. This is because spacer 442 keeps mid-panel426 raised enough so that as wound 16 is raised as the joint bends,wound 16 will not be interfered with by mid-panel 426. (See FIG. 32.)

Illustratively, and in similar fashion to previous embodiments, tube 382deposits medicinal fluid into chamber 424 where it flows throughpassageways 377 into cavity 428. An outlet tube 448 is extendedillustratively through top panel 422, over spacer 442, and into woundcavity 428. Notches 346 can be formed in the length of tube 448positioned within cavity 428 so that after the fluid has deposited ontowound 16 it is drawn up through opening 437 and/or notch 346 into outlettube 448. Like previous embodiments, it is understood that the flow ofthe medicinal fluid can be reversed. The fluid can be deposited ontowound 16 by tube 448 and drawn up through passageways 377 into chamber424 and out tube 382.

A further embodiment of the present invention comprises a heat and heatsensing system 500 (collectively, heat system 500) coupled,illustratively, with bandage 499 as shown in FIG. 33. It is appreciatedthat heat system 500 can be coupled with any bandage described herein.Heat system 500 includes a heating and sensing pad 502, thermocouples508 and 510, a tube assembly 504, and a patch unit connector 506. Pad502 is the portion of system 500 that transfers heat to bandage 499 aswell as senses the amount of heat that was transferred. Illustratively,pad 502 includes a thermocouple 508 that supplies heat to pad 502, SeeFIG. 34. A second thermocouple 510 senses the heat that is beingsupplied by thermocouple 508. Pad 502 can be made, illustratively fromsilicone, but it is appreciated that pad 502 can be made from anysuitable material serving the same function as silicone. Pad 502 can beeither inserted into a pocket 503 within the bandage or coupled to thebandage by any suitable means. In addition, alternatives to pad 502 canbe used to transfer heat from thermocouple 508 to bandage 499. Boththermocouples 508 and 510 extend from pad 502 to patch unit connector506. Illustratively, the thermocouples can be contained in tube 504protecting same. Tube 504 can be flexible and made from any suitablematerial, and be of any suitable length.

Patch connector 506 connects to a nebulizer cartridge (not shown) andcan be removed for continual use on additional bandages. A double lumentube 512 can connect to tube connector 513 to supply medicinal fluid tobandage 499 and draw fluid away from same, as hereinbefore described.

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe scope and spirit of the present invention as described and definedin the following claims.

1. A wound treatment apparatus comprising: a bandage including a woundfacing surface configured to face toward a wound and a fluid drainagepassageway having an opening adjacent the wound facing surface; a fluiddrainage tube coupled to the fluid drainage passageway; first and secondfluid drainage receptacles coupled to the drainage tube; and first andsecond valves coupled between the fluid drainage tube and the first andsecond fluid drainage receptacles, respectively.
 2. The apparatus ofclaim 1, wherein the valves are pinch valves.
 3. The apparatus of claim1, further comprising a sensor coupled to the first fluid drainagereceptacle to provide a signal indicative of an amount of fluid in thereceptacle.
 4. A bandage for use with a wound treatment apparatus havinga negative pressure source, the bandage comprising a first sheetoverlying a wound and located adjacent to it and a top sheet overlyingthe first sheet, the first sheet having a plurality of discretepassageways overlying the wound and adapted to communicate negativepressure established by the negative pressure source to the wound. 5.The bandage of claim 4, wherein the plurality of passageways in thefirst sheet comprises a plurality of apertures that are arranged to lieon a circle.
 6. The bandage of claim 4, wherein the first sheet isclear.
 7. The bandage of claim 4, wherein the first sheet is flexible.8. The bandage of claim 4, wherein the first sheet is impermeable. 9.The bandage of claim 4, further comprising an element that adheres tohealthy skin adjacent the wound and the first sheet is coupled to theelement.
 10. The bandage of claim 4, wherein at least some of theplurality of discrete passageways in the first sheet are adapted tocommunicate fluid from a fluid source of the wound treatment apparatusto the wound.
 11. The wound treatment apparatus of claim 4, wherein thetop sheet does not have any openings therethrough to provide a vacuumspace above the wound.
 12. A bandage for use with a wound treatmentapparatus having a negative pressure source, the bandage comprising afirst sheet and a second sheet, the first sheet overlying a wound andlocated adjacent to it, the first sheet having a plurality of discretepassageways adapted to communicate negative pressure established by thenegative pressure source to the wound, the second sheet having at leastone discrete passageway that communicates with at least one of theplurality of discrete passageways of the first sheet.
 13. The bandage ofclaim 12, wherein the first sheet has a first outer perimeter, thesecond sheet has a second outer perimeter, and the first outer perimeteris aligned with the second outer perimeter.
 14. A bandage for use with awound treatment apparatus having a negative pressure source, the bandagecomprising a first sheet with a plurality of discrete passagewaysadapted to communicate negative pressure established by the negativepressure source to a wound, a second sheet coupled to the first sheet,and an element coupled to the second sheet that adheres to healthy skinadjacent the wound.
 15. A bandage for use with a wound treatmentapparatus having a negative pressure source, the bandage comprising afirst sheet overlying a wound and located adjacent to it and a top sheetoverlying the first sheet, the first sheet having a plurality ofdiscrete apertures overlying the wound and adapted to communicatenegative pressure established by the negative pressure source to thewound.
 16. The bandage of claim 15, wherein at least some of theplurality of discrete apertures in the first sheet are arranged to lieon a circle.
 17. The bandage of claim 15, wherein the bandage comprisesa second sheet coupled to the first sheet and located between the firstsheet and the top sheet, and the second sheet has at least one discreteaperture, but has a lesser number of discrete apertures than the firstsheet.
 18. The bandage of claim 17, wherein the first sheet has a firstouter perimeter, the second sheet has a second outer perimeter, and thefirst outer perimeter is aligned with the second outer perimeter. 19.The bandage of claim 15, wherein the first sheet is clear.
 20. Thebandage of claim 15, wherein the first sheet is flexible.
 21. Thebandage of claim 15, wherein the first sheet is impermeable.
 22. Thebandage of claim 15, wherein the top sheet does not have any openingstherethrough to provide a vacuum space above the wound.
 23. The bandageof claim 15, further comprising an element that adheres to healthy skinadjacent the wound, the bandage comprises a second sheet located betweenthe first sheet and the top sheet, the first sheet is coupled to thesecond sheet, and the second sheet is coupled to the element.
 24. Thebandage of claim 15, wherein at least some of the plurality of discreteapertures in the first sheet are adapted to communicate fluid from afluid source of the wound treatment apparatus to the wound.